U0109: Lost Communication with Fuel Pump Control Module
Standardized SAE J2012 code · U01xx — Lost communication with modules
What does U0109 mean?
The Fuel Pump Control Module has stopped transmitting on the vehicle data bus, so other control units no longer receive its messages. Fuel-delivery control is lost, which can starve the engine of fuel. Typical causes are loss of power or ground at the module, an open or shorted CAN/LIN bus wire, a connector fault, or an internal module failure.
The code tells you which monitor failed, not which part is broken. Test before replacing parts.
Symptoms
- Multiple warning lights may illuminate
- Affected modules may go into limp mode or shut down
- Specific functions inoperative depending on module
- Diagnostic tools may show communication faults
Common causes
- High Fuel pump module unpowered (often a fuse or relay)
- Medium CAN wiring to FPCM broken
- Low Gateway module routing CAN messages incorrectly
Likelihood is a general estimate across vehicles; your make and model may differ.
Add your car to see reports of U0109 on the same make and model first.
U0109 in the community
Ask about U0109No one has posted about U0109 yet
Share your vehicle, the tool you used and what you tested — the first thread helps everyone who searches for this code.
Describe your U0109 problem